Ribbed lath



J. W. PEARCE Dec. 20, 1932.

RIBBED LATH Filed July 50, 1930 Patented Dec. 20, 1932 JAMES W. PEAR-CE,OF PHILADELPHIA, PENNEYLVANIA RIBIBED LATE Application filed July so,

This invention relates to improvements in ribbed lath and method ofmaking the same and it consists of the matters hereinafter described andmore particularly pointed out 5 in the appended claims.

The lath with which the invention is particularly concerned includeslongitudinal areas of open work or mesh fabric bounded along each sideby an upstanding rib. Such lath is extensively used as a reinforcementin concrete work and heretofore the ribs were substantially openV-shaped ones with the side walls thereof spaced apart so that when usedin concrete for fioor slabs, the reinforcing efiect of such ribs isindeed small.

The primary object of the invention is to provide a lath of this kindwherein the ribs thereof are formed for greater strength as well asgreater adherence and reinforcing properties when used in concrete.

Another object of the invention is to provide a lath of this kindwherein the side walls of the ribs are formed to provide a laterallydisposed flange, either hooked or straight which overhangs but is spacedabove the body of the lath and imparts a rigidity and a concreteretaining action to said ribs which is not present in the conventionalribbed lath as now made.

Another object of the invention is to provide a method wherebyconventional rib lath may be operated upon in a manner transforming theusual open V-shaped ribs into substantially closed ones having a lateraloverhanging flange whereby each rib is made stronger and more rigid toresist collapse and has a better bonding and reinforcing action in anyconcrete in which the lath may be used.

These objects of the invention as well as others, together with the manyadvantages thereof, will more fully appear as I proceed with myspecification.

In the drawing Fig. 1 is a fragmentary perspective view of a shortlengthof ribbed lath embodying my invention.

Fig. 2 is a transverse vertical detail sectiona1 view through a piece ofconcrete slab in 1930. Serial N0. 471,648.

which my improved lath is imbedded as the reinforcing element thereof.

Fig. 3 is a transverse vertical detail sectional view on an enlargedscale through a I lath rib embodying one form of my invention.

Figs. 4 and 5 are views similar to Fig. 3 showing modified forms of theinvention.

Fig. :3 transverse vertical sectional view through a conventional formof J- shaped lath rib and from which a lath rib embodying my inventionmay be readily produced.

Fi 7 is a view showing the first step of operating upon a conventionalV-type rib to provide a rib embodying one form of my invention.

Fig. 8 is a view showing the next step of transforming the partiallyformed rib of Fig. 7 into a rib embodying one form of my invention asfor instance that form of rib shown in Fig. 3.

Referring now in detail to that embodiment of the invention illustratedin the drawing and especially to Figs. 1, 2 and 3 thereof, 1 indicatesas a whole a portion of a sheet of ribbed lath which includeslongitudinally extending relatively wide bands 2-2 of open mesh andpreferably expanded metal fabric and intermediate and marginal ribs 33.

Each rib in this instance comprises a pair of substantially upstandingside walls t-i which engage each other at their top ends 5 to thereprovide a double thickness and diverge from each other at their bottomends as at 6, the said double thickness top end of the rib being turnedover laterally and downwardly on a curve to form a hook flange 7 givingthe rib a cross sectional shape which approximates an inverted letter J.

When such a lath is imbedded in a slab of concrete 8 as shown in Fig. 2,the hook-like ribs have a greater retentive property because of thelodging of the concrete under the same. Such ribs are indeed stiff andrigid and will not collapse under the action of the wet concrete as thesame is poured to form the slab nor will such ribs be deformed laterallyor in the plane of their height.

In Fig. 4, I have shown a rib wherein the side walls are formed asbefore and the double thickness top end thereof is bent over laterallyto one side, and left straight without turning down, to form a flange 7Such a flange lends a cross sectional shape to the ribs thatapproximates an inverted letter L. Instead of the flange being formed toproject laterally from but one side of the rib, it may be formed toproject laterally from both sides as shown at 7 in Fig. 5. Such a flangearrangement lends a cross sectional shape to the rib that approximates aletter T.

In each of the ribs shown in Figs. 3, i and 5, the bottom margins of therib walls are spread slightly apart and this spread helps to bra e saidwalls in upright position against bending over, in the pouring of theconcrete, which bending ever would be more possible if the two wallsengaged each other through- 210. ut their entire height.

The ribs may be formed at the time of fabricating the sheet or they maybe formed from previously made conventional type of V-shaped ribbed lathnow obtainable in open market. In Fig. 6, I have iilustrated aconventional type of V-shaped rib comprising a pair of converging sidewalls t -et joined together at the top by a rounded web at". Such sidewalls are brought together for the greater portion of their heightdownwardly from said web to give a slight spread only at their bottommargins where one or both oin the sheet so that such walls now providean upright substantially double thickness rib as best shown in Fig. 7,after which the top marginal portion of the rib is bent over laterallyand downwardly to provide the hook flange 7 to give the inverted J-shapecross section to the rib as before mentioned. In this manner I amenabled to take the conventional V shaped ribbed lath and by running itthrough a flange forming machine, not only increase its rigidity, butalso its qualities as a reinforcing element for use in concrete whereina better bonding action is afforded between such an element and saidconcrete. In thus forming the ribs from conventional V-shaped ribbedlath, only a slight difference occurs in the width of such lath and withsubstantially no difference in height of the rib but the ad vantagegained in its reinforcing qualities more than offsets such slight lossin area as may occur in the transformation of such lath. lVhen lathembodying my invention is used as a foundation for plaster, it reducesthe formation of cracks therein in line with the ribs, which cracks arequite common when the \/-type deep rib lath is used for this purpose.lVhile in describing the invention I have referred in detail to the formarrangement and method of making up the various portions of the lath,the same is to be considered merely as illustrative so that I do notwish to be limited thereto except as may be specifically set forth inthe appended claims.

I claim as my invention 1. An integral metallic sheet for reinforcingconcrete, plaster and the like having a plurality of open work flatportions therein with a rib along each side of each fiat portion, whichrib includes a pair of substantially upright, closely adjacent integralside walls at least one of which is integral with the sheet, a portionof the side walls of each rib being bent laterally to provide a doublethickness integral flange overhanging the associated open work flatportions of the sheet but spaced above the same each rib having a V-shaped opening between the lower portion of the walls.

2. An integral metallic sheet for reinforcing concrete plaster and thelike having a plurality of flat portions therein with a rib along a sideof each flat portion, which rib includes a pair of substantially uprightside walls meeting each other at the top of a V-shaped opening, theopening extending only a short distance from the portion between theupright side w lls, at least one of which walls is connected to thesheet, a portion of both the side walls of each rib being bent laterallyand then curved downwardly to provide a double thickness hook flangeoverhanging and spaced above an associated flat portion of the sheet.

In testimony whereof, I have hereunto set my hand, this 23rd day ofJuly, 1930.

JAMES IV. PEARCE.

